Gate for railroad crossings



Sept. 15, 1925.

. F. P. MANSFIELD GATE FOR RAILROAD CROSSINGS 2 Sheets-Sheet 1 Filed Sept. 50, 1922 u-iii lll-lllllll l Frank E. Mansfield finewse t. so, 1922 -2 Skins-Shun 2 Frank P 'Mansfield Patented Sept. 15, 1925.

UNITED STATES FRANK P. MANSFIELD, CF MILWAUKEE, WISCONSIN.

GATE roe RAILROAD onossiues.

Application filed September 30, 192 2. Serial l lo.

To all whom it may concern:

Be it known that I, FRANK P. MA SFIELD, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of VVi'sconsin, have invented. certain new and useful Improvements in" Gates for Railroad Crossings; and I do hereby declare that the following is a full, clear, and exact description thereof.

This invention relates to gates for railroad crossings, and is particularly directed ,ter-balanced gate arm; to provide electrical means controlled from the tracks for lowering the gate arm against the action of the counterbalance; to provide means for electromagnetically retaining the gate in closed position, and to provide means for releasing such gate to allow it to return to its initial position.

An embodiment of the invention is shown in the accompanying drawings, in which Figure 1 is a side elevation partly broken away of the railway gate, showing certain of the operating parts in sectional elevation.

Figure 2 is a side elevation 'ofthe structure shown in Figure 1, with the outer casing or door removed.

Figure 3 is a diagrammatic View showing the electrical connection for the various de' vices.

The gate comprises a stationary housing or casing 1, within which is mounted the op erating mechanism, switches, and controlled device. A transverse shaft 2 passes thru such casing, and rigidly carries the gate arm ,3, which, the form shown, may be a pair of arms spanning the casing 1. These arms are counter-balanced bymeans of the weights 4, so that the gate tends to return to its upright or open position. A switch base 5 is rigidly mounted within the casing,

and is provided with a series of stationary rings which will be described in detail later. A movable contact 6 is adapted to slide upon one face of this base 5, and, is carried by an arm 7 rigidly attached to the shaft 2. A second movable Contact 8 is carried by a relatively large gear 9, loosely mounted upon the shaft 2. Adjacent the machined outer face 01 this gear, is mounted an electromagnetic clutch 10, which is securely keyed to the shaft 2. A brake drum 11 is mounted fast upon the shaft 2 and is surrounded by a brake band 12, controlled by an electromag netic brake 13. A series of slip rings 14 and 15 are mounted upon this shaft and supply various circuits. The gear 9 is adapted to be driven thru reduction gearing 16, by means of an electric motor 17. It will be seen, therefore, that-the switch 6 is connect ed to the gate and the switch 8 is connected to the motor through the reduction gearing.

A drum 18 is rigidly mounted upon the shaft 2, and operates the cable 19, which passes over the pulley 20 located adjacent the lower portion of the casing, and is adapted to pass to a dummy gate, or gates, mount ed upon the other side of the crossing to cause, a simultaneous operation of the arm of the dummy gate. An electric bell 21 may be carried upon an arm 22 supported from the casing, and a series of lights 28 may be mounted upon the gate arm 3.

: Figure 3, showing the electrical systems for the various portions of the device, will now be described :--In this figure, the insulated sections of the track are indicated at 24:, and such sections are connected to a battery 25 in a well known manner. A pair of leads pass from these tracks and connect with a track relay 26, such relay having a movable armature 27 tending to be drawn away from the magnet by means of a spring 28. In the position of the parts shown in Figure 8, the master relay is shown energized, which is the position normally assumed in a closed circuit system, such as shown in this figure. Vhen, however, the tracks 24 are bridged by the wheels and axles of a train, the track relay is de-energized and the armature closes the main circuit by bridging the contacts 29 and 30. In

the form of the invention shown, the source charged by means of a rectifier 32 from alternating current mains 33. It is, however, to be distinctly understood that the storage battery may be dispensed with and the system directly operated from the mains, if it is desired.

The rectifier 32 will not be described. in detail, except to state that it is of the automatic variety adapted to charge the storage battery whenever such batterys terminal voltage has dropped below a predetermined value. The main circuit is additionally manually controlled by means of a plunger 34, operatively connected to a door, not shown, in the main casing 1 of the gate, so that when such door is opened, the main circuit is also opened, thereby providing a manual control for the gate operating in conjunction with the automatic control.

The positive side of the battery is connected to the contact 30, and the circuit passes from such contact thru the armature 27, when the track relay is deenergized, to the contact 29, From thence it passes to the lead 35 and branches from such lead, dividing it into two distinct circuits, the first of such circuits including the bell 21 and the lights 23, and returning to the negative side of the battery by means of the lead 36. The second portion of this circuit passes to the continuous ring or stationary contact 37, mounted upon the supporting base 5 of the switch mechanism. This ring may conveniently be the outer ring of a series of concentric contact rings carried upon the face of the plate 5 adjacent the large gear 9. In the form shown in Figure 3, the next ring is provided with a large portion 38, and with a smaller portion 39 connected by means of "the lead 40 with the motor 41, the return circuit of the motor passing thru the lead 36. The next ring has a portion 42 connected to the clutch 10, the circuit passing from such clutch ring back to the return lead 36. The fourthring has a portion 43 connected with the electromagnetic brake 44, by means of the conductor 45, the return portion of the circuit oining the lead 36. It is to be noted that the two innermost rings are not shown as completely formed, but only the active portion of the rings have been shown. It is of course understood that the slidable contact 8, or brush, may travel either upon the surface of the plate 5, or upon a continuation of the members 42 and 43, such continuation, of course, being electrically distinct from therportions 42 and 43. The other face of the plate 5 is provided with a pair of stationary contacts 46 and 47, which are adapted to be bridged by the brush or movable contact 6 when the gate is in its vertical position. These portions 46 and 47 may be supplemented by an electrically distinct continuation thereof, forming a bearing ring for the brush 6 to operate upon, or such portions may be relatively short, as shown in Figure 3. They are connected respectively, to the segments 39 and 38. I

The operation of the automatic gate is as follows :When a train arrives at the insulated portion 24 of the tracks, the track relay is de-energized, and the main circuit is closed by its armature 27, which, under the influence of the spring 28, moves to a position bridging the contacts 29 and 30. This allows the battery 31 to send current from its positive terminal thru the conductor 48, the conductor 35 to the continuous ring 37. From this ring, current passes along the brush or arm 8 to the segment 38, from thence to the segment 47, thru the arm or brush 6, to the segment 46, from thence to the segment 39, conductor 40 thru the motor 41, and to the return conductor 36. The.

motor, therefore, begins to function and op- 1 crates the large gear 9 thru the reduction gearing, causing the arm 8 to swing around the shaft 2, until it joins the ring 37 with the segments 39 and 42. It will be noted that the joining of the segments 37 and 42 establishes an auxiliary circuit,one extending from the ring 37 thru the clutch 10, thru the conductor 49 to the return conductor 36. The clutch, therefore, locks to the gear 9 and causes the shaft 2 to rotate, thereby lowering the gate arm. When the gate arm is substantially horizontal, it will be noted that the arm 8 has reached the full line position, shown in Figure 3, and that the motor circuit and clutch circuit are each interrupted and a new circuit established from the ring 37 to a segment 43, thru the conductor 45, thru the brake solenoid 44, and back to the return conductor 36. In this connection it is to be noted that the momentum of the rotating parts will carrythe brush or arm 8 to the position shown, and that when it arrives in such position, the brake locks, thereby retaining the arm in its lowered position. hen the train passes from the insulated portion 24 of the tracks, the track relay is energized, thereby opening the main circuit and causing the brake to release and the lights 23 and bell 21 to cease functioning. W hen the brake releases, the counter balance 4 will cause the arm 3 of the gate to assume itsvertical position, and the parts will then again be in the positions shown in Figure 3.

It is tobe noted that although the motor operates to-\ rotate the arm 8 the gate arm 3 does not function until the arm 8 has reached a position slightly past vertical, at which time the clutchis energized and arm 3 commences to travel downwardly. The auxiliary brush 6 provides a means for temporarily connecting the segments 38 and 39, so as to permit. the starting of the motor when the track relay functions and the parts are in the positions shown in Figure 3.

It will be seen that an automatic gate has been provided, in which both manual, namely the plug 34:, and automatic means have been provided for jointly controlling the operation of the gate arm, and of the visual and audible signals.

It will also be seen that means have been provided for retaining the gate in its closed position against its tendency to return, until such time as a train shall have passed from the insulated section of the track.

It will also be seen that this system is adapted to operate either with a closed circuit type of control from the tracks, such as shown in Figure 3, or with an open circuit type of control, by merely placing the battery 25 in the relay circuit for the latter type of control.

Although the system has been described as particularly applied to one supplied by a main battery 31, it is to be understood that any suitable source of electric energy may be employed, that is to say, if it is found desirable, the battery may be dispensed with and the system directly opeiated from the mains.

lVhile one specific form of the invention has been described in considerable detail, it is to be understood that the invention may be embodied in several \idely different forms, and that it is therefore to be limited only as defined in the appended claims,

I claim:

1. A gate for a railway crossing comprising a track relay controlled from the railway tracks, a source of electric energy, an automatic rotary switch connected to said source and controlled by said relay, a gate arm biased toward upright position, an electric motor, a magnetic clutch for operatively coupling said motor and arm and controlled by said rotary switch, and a brake for holding said arm in lowered position and controlled jointly by said relay and switch, said rotary switch adapted to be operated by said motor.

2. In an automatic gate for a railway crossing the combination of a pivoted gate arm biased toward upright position; rotary mechanism associated with, but normally free from said arm; an electric motor mechanically coupled to said rotary mechanism; an electromagnetic clutch for temporarily coupling said rotary mechanism and said arm; an electromagnetic brake for holding said arm in lowered position; and

a two part electric switch controlled jointly by said rotary mechanism and said arm for controlling the electrical circuits of said motor, clutch and brake in a regular sequence, said motor, clutch and brake being also controlled from the railway tracks.

3. In an automatic gate for a railway crossing, the combination of railway tracks of a gate arm, an electric motor, an electror ignetie clutch for operatively coupling said arm and motor, a track relay controlled from said railway tracks and controlling said motor and clutch, a switch operatively associated with said motor, a second switch operatively associated with said arm, both of said switches additionally controlling said motor and said first mentioned switch additionally controlling said clutch.

4. In an automatic gate for a railway crossing, the combination of railway tracks, a gate arm; an electric motor; an electromagnetic clutch for operatively coupling said arm and motor; electromagnetic means for retaining said arm in closed position; means for returning said arm to open position; a track relay controlled from said tracks and controlling said motor, clutch, and electromagnetic means; a switch open ated from said arm for additionally controlling said motor; and a second switch operated from said motor for additionally controlling said motor, clutch, and electromagnetic means.

5. In an automatic gate for railway crossings, the combination of railway tracks, a gate arm, an electric motor, an electromagnetic clutch for operatively connecting said arm and said motor, a track relay having a track circuit and controlled from said railway tracks and controlling said motor and said clutch, a switch driven from said motor for controlling said clutch and motor, a switch movable with said gate arm and additionally controlling said motor, a friction drum movable with said gate arm, an electromagnetic brake having a movable portion adapted to directly engage said friction drum, said brake being controlled by said first mentioned switch, the circuitsof said motor, clutch and brake being independent.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of vVisconsin.

FRANK P. MANSFIELD. 

